PCR: The technique PCR: Contributions to the Study of Ancient DNA The Advantages of PCR The Disadvantages of PCR Control Methods and Percautions Glossary Need more info? (References) About the Author

The Basics of Polymerase Chain Reaction

The Polymerase Chain Reaction (PCR) invented by Kary Mullis in 1986 is one of the most important techniques used in the study of ancient DNA (McMurry, 2000). PCR is an amplification technique, capable of producing multiple copies of a desired DNA sequence for analysis (McMurry, 2000). The overall process of PCR involves carrying out repeated cycles of heating and cooling of the DNA sequence. Its use is applicable in many studies including the study of the extinct quaqqa, bones from the Cretaceous Period, Neandertal bones, and the Siberian mammoth. As an alternative to Cloning, PCR has the advantage of being highly efficient, selective, and accurate method of amplification. However, PCR is not perfect and often encounters a number of problems in studying ancient DNA. These problems include Jumping PCR, and difficulty in amplifying damaged or contaminated DNA sequences. Fortunately, using various control methods can minimize these problems. Although in a non-ideal world, PCR is not perfectly successful in obtaining DNA sequences, it has made many contributions and is vital to the study of ancient DNA.

In spite of the problems associated with PCR, it has many applications in the study of ancient DNA. PCR is comparatively more efficient, selective and accurate as compared to Cloning. Its simple and efficient technique makes it possible to produce enough copies for the study of genealogical relationships of extinct species and vanished populations, particularly in examining the extinct quaqqa, bones from the Cretaceous Period, the Siberian mammoth, and Neandertal bones. Even though many problems such as contamination, and misincorporations by the TP due to damaged molecules or jumping PCR are unavoidable, various control methods and estimations can be taken to estimate and minimize their effect. Nonetheless, PCR has made consistent findings in all above applications and its invention is unquestionably vital in the study of ancient DNA.